There is known a conventional robot in which an end effector is attached to a leading-edge arm such as a wrist unit coupled to a robot arm and that swings the leading-edge arm and rotates the end effector by using a motor provided inside the robot arm to automatically perform a predetermined operation.
In this robot, a drive pulley attached to the motor and a driven pulley attached to the swing axis of the leading-edge arm and the rotation axis of the end effector are coupled by an endless belt in an interlocking manner. The robot has been known as disclosed in, for example, Japanese Laid-open Patent Publication No. 2010-094749. As a result, a driving force of the motor is transmitted to the swing axis of the leading-edge arm or the rotation axis of the end effector.